George henry challenges



G. H. CHALLENGER AND H. A. SAVAGE.

AIRCRAFT.

APPLICATION FILED JULY 6.1911.

Patented Aug. 5, 1919.

UNITED STATES PATENT @FFTQE.

GEORGE HENRY CHALLENGER, OF WESTMINSTER, LONDON, AND HAROLD ARTHUR SAVAGE, 0F BEXLEY HEATH, ENGLAND, ASSIGNORS TO VIGKERS LIMITED, 0F

' WES'I'MINSTER, ENGLAND.

AIRCRAFT.

Specification of Letters Patent.

Patented Aug. 5, 191?).

Application filed July 6, 1917. Serial No. 179,089.

CIIADLENGER and HAROLD ARTHUR SAVAGE,

both subjects of the King of Great Britain, residing, respectively, at Vickers House, Broadway, Westminster, in the county of London, England, and Bexley Heath, in the county of Kent, England, have invented certain new and useful Improvements in or Relating to Aircraft, of which the following is a specification.

This invention relates to aircraft and particularly to aeroplanes of the tractor type carryingan automatic, a semi-automatic or a single fire gun adapted to fire in a forward direction between the blades of the propeller; the invention may also be employed in connection with guns carried by aeroplanes of the pusher type and adapted to fire' in a rearward direction between the propeller blades.

In the specification of our concurrent British Patent Application No. 1324 of 1916, we have described apparatus controlled by the movements of the propeller for firing the gun only when the bullets would pass between and miss the propeller blades. It

has been found in practice that with some types of automatic gun the lapse of time between the making of the electrical contact in the case of electrical control apparatus and the arrival of the bullet contiguous to the propeller is relatively long; it may for example be one tenth of a second, and during this lapse of time the propeller will have made two complete revolutions when running at twelve hundred revolutions per minute. With a mechanical control apparatus a similar result occurs although the interval of time may be somewhat smaller. In both cases it can'only be assumed with safety that the bullet will pass between the propeller blades without striking them when the variation in the propeller sp'eeddoes not depart by more than say two hundred revolutions per minute from the normal.

According to the present invention in order to obtain a greater range of safety we provide a governing device which will automatically advance or retard the instant at which the control apparatus is brought into operation, in accordance with the speed variations of the propeller, this governing device being of such a character that it will not be influenced appreciably by gravity or by acceleration of the aeroplane as would be the case with a centrifugal type of governor;

In order that the said invention may be clearly understood and readily carried into effect we will describe the same more fully with reference to the accompanying drawings, in which Figure 1 is a sectional view showing more or less diagrammatically a constructional form of the governing device,

Fig. 2 is a section taken approximately on thfe line 1, l of Fig. 1 looking toward the le t,

Fig. 3 is a diagrammatic side elevation showing the invention applied .to an auto matic gun, and

Fig. 4 is a section of the rear portion of the gun and its parts of Fig. 3.

In the example shown the governing device is employed in conjunction with a mechanical control apparatus comprising an operating cam A which is mounted upon a shaft a, carrying a pinion a which meshes with a gear wheel driven in any suitable manner from the propeller engine A of Fig. 3. The cam A operates upon the sear of the gun, through a push rod a" whose rear end is connected to'a lever (19" having a pawl a engaging with the usual trigger lever A (Fig. 4:) of the Vickers automatic gun so that when the rod a is pushed by the cam A the trigger lever A will be operated to release the scar and fire the gun in the usual manner. The said cam is connected to a plate or nut A which engages with helical fins or threads on the shaft 0. The cam and the plate A are prevented by brackets a a from moving axially with the shaft a and the latter is .connected to a piston B in such manner thatthe latter does not rotate with the shaft although the piston and the shaft can move together axially. In the example shown this is effected by the stepped enda of the shaft running loosely in a box 6* on the piston which is retained on the shaft by a nut and pin. washers a a being provided between the nut and the boss and between the said boss and theshoulder a on the shaft. This piston is disposed within a cylinder B whose end portions are connected by a supply pipe 6 and a return pipe 7) to a pump, such as the intermeshing pump shown, which delivers oil or a mixture of gylcerin and water-to the left hand end of the cylinder B, thereby causing the pis: ton B to be displaced in'the cylinder against the resistance of a spring "18. to an extent depending upon the speed of the pump .which is driven from the propeller.

shaft a movesjaxially with the pistcn B through a stufing box a on the cylinder and the camel is angularly displaced in relation to the shaft by the helical fins or threads on the latter tovary the instant at which the cam operates the searof the gun. The pinion a is connected to the shaft a by a feather a and is prevented'as shown from moving axially with the shaft.

The piston is formed with a keyway b in which is disposed a tapering key I) attached to the cylinder B, this arrangement" giving a variable orifice by which the liquid can escape from the left hand side to the right hand side of the piston. In this manner we can insure that the-distance of theof means controlled by the movements of the propeller for 'firingsaid gun and "a govern ing device forautomatically varying the instant at which the said means come into operation in accordance with the speed variations of the propeller.

The,

neaacee '2. lhe combination with an aircraft gun adapted to fire between the propeller blades, 'of means controlled by the movements of the propeller for firing said gun, a spring controlled member, a pump dr ven by the propeller engine for actuating said' member in opposition to the spring and means,-operated by the movements of said member, for varying the instant at which the first mentioned means come into operation to fire the gun.

3. Thecombination with an aircratt gun adapted to fire between the propeller blades, of means'conti'olled by the movements of the propeller tor firing said gun, a'spring .con-

trolled piston, a cylinder in which said piston works, a variable orifice being provided between the piston and the-cylinder, a liquid pump driven b the propeller engine for supplying liqui to the cylinderto actuate said piston in opposition to the spring, and means, operated by the movements of the piston, for varying the instant at which the first mentioned means come into operation to fire the gun.

i. The combination with an airci ft gun adapted to fire between the propeller blades, of a cam for firing the gun, a shaft on which the cam is mounted, means for rotating said Yshaft from the propeller engine, a spring" controlled piston connected to the shaft, :1 cylinder in which said piston works, a pump driven by the propeller engine for supplying fluid to the cylinder to actuate said piston in opposition to the spring, and means interposed between the shaft and the cam whereby sliding movement of the shaft will alter the timing of the cam.

' In testimony whereof we affix our signatures.

eroresasrar CHALLENGER, HAROLD ARTHUR 'SAVAGE.- 

